Immunology Flashcards
What features of the eye’s immune protection are unique?
No physical barrier
Not many commensal bacteria
What are the physical features of the eye’s immune protection?
Blink reflex
Tears
Mucous layer
What are the chemical features of the eye’s immune protection?
Tears
Lysozyme
Complement
What are the immune cells in the eye?
Neutrophils
Macrophages
Conjunctival mast cells
What is the principle antigen presenting cell for the external eye?
Langerhans cells
Where are langerhans cells present and absent in the eye?
Abundant in corneo-scleral limbus
Less in peripheral cornea
Absent from central 1/3 of cornea
What is the only part of the eye with lymphatic drainage?
Conjunctiva
What type of tissue that is important for immune protection is present in the conjunctiva?
MALT (mucosa associated lymphoid tissue)
How do the cornea and sclera give immune protection?
As a tough collagen coat
Do the cornea and sclera have good immune protection - and why?
No Avascuar No lymphatics or lymphoid tissue Relative lack of APC Langerhans cells only in peripheral cornea
What is the term that describes the lack of immune protection in the cornea and sclera (and other parts of the eye)?
Down regulated immune response
How does the lacrimal gland and drainage system contribute to immune protection?
More plasma cells and CD8+ T cells
Drainage system has MALT
What immune protection do the vitreous, choroid and retina have?
Blood-ocular barrier - tight barrier restricts movement of anything in and out of important components of the eye
What ares of the eye have a down regulated immune response?
Cornea Sclera Vitreous Choroid Retina
What is immune privilege?
The ability of certain parts of the body to tolerate the introduction of antigens without eliciting an inflammatory immune resoonse
Which sites in the eye have immune privilege?
Cornea Anterior chamber Lens Vitreous cavity Subretinal space
What is sympathetic ophthalmia?
Rare granulomatous uveitis in both eyes that occurs due to trauma or surgery to one eye
In sympathetic ophthalmia what are the terms for each eye?
Injured eye is the exciting eye
Fellow eye is the sympathising eye
How do you determine which is the exciting and sympathising eye in sympathetic opphthalmis?
Cant tell clinically - just from history
What is an example of a type 1 hypersensitivity reaction in the eye?
Acute allergic conjunctivitis
What is an example of a type 2 hypersensitivity reaction in the eye?
Ocular cicatricial pemphigoid (autoimmune)
What is an example of a type 3 hypersensitivity reaction in the eye?
Autoimmune corneal melting
What is an example of a type 4 hypersensitivity reaction in the eye?
Corneal graft rejection
What are some ocular side effects of steroids?
Cataracts
Glaucoma
